Adjustable dipole antenna unit



Oct. 20, 1942. A. FENER ADJUSTABLE DIPOLE ANTENNA UNIT Filed Nov. 24, 19 41 2 Sheets-Sheet l v INVENTOR.

FL FRED FEE/ BY 4,6 of

HTTOR/VEY INVENTOR. FFL FRED FENEI? ATTORNEY A. FENER -ADJUSTABLE DIPOLE ANTENNA UNIT Flled Nov 24 1941 2 Sheets-Sheet 2 Patented Oct. 20, 1942 UNITED STATES PATENT OFFICE ADJUSTABLE DIPOLE ANTENNA UNIT Alfred Fener, Brooklyn, N. Y.

Application November 24, 1941, Serial No. 420,229

8 Claims.

The present invention relates to adjustable antenna units. and, more particularly, to an adjustable di-pole antenna unit of novel and improved character.

As those skilled in the art know, the di-pole antenna, or di-pole, has acquired great popularity in recent years and is at present considered the preferred antenna system particularly in the reception of short-wave, television and frequencymodulated signals. The di-pole essentially comprises a pair of metallic rods having a length which is in part determined by the wave-length of the signals to be received. These rods are generally mounted in a substantially linear direction with respect to each other and are individually or collectively connected to a transmission line. The signals picked up by the di-pole are transferred through said line to the receiving set either directly or through a suitable coupling device. The two rods of the di-pole may be arranged in a horizontal or in a vertical direction according to whether horizontally or vertically polarized waves are to be principally received. In some cases a horizontal and a vertical di-pole have been combined into a single unit comprising four rods arranged in radial direction, 90 degrees from each other. 4

Generally speaking, it has been found desirable to adjust the rods of the di-pole in order to obtain optimum conditions of reception, greatest freedom from interference and local disturbances and to conform to local mechanical conditions at the place of mounting or installing the antenna unit. Therefore. di-pole units were frequently provided with adjustable mounting elements to permit adjustment of the antenna rods in a plurality of planes and to permanently fix the rods in such adjusted position. These mounting elements, or systems. had to satisfy a plurality of important conditions. Thus, they had to provide simple and positive adjustment of the rods in a plurality of planes and positive fixing thereof after the desired adjustment has been obtained. In addition, they had to provide proper and satisfactory insulation of the rods under all operating conditions and to maintain such insulation against the influence of atmospheric conditions. Moreover, the mounting unit had to be mechanically simple and rugged so that it would stand up and would operate properly without any servicing or additional adjustment for a relatively long time. From the foregoing considerations, it is clear that the problem of providing a completely satisfactory adjustable di-pole antenna unit was a very complex one.

It is the principal object of the present invention to provide an adjustable di-pole antenna unit of novel and improved character which represents a substantial improvement over prior devices of the described character.

It is another object of the present invention to provide an adjustable di-pole unit particularly for mounting on a pole, which can be readily adjusted on the pole with respect to its height and direction and which may be easily and positively fixed in such adjusted position.

It is a further object of the invention to provide an adjustable di-pole comprising at least one pole-engaging element, displaceably and rotatably mounted with respect to the pole, capable of being positively fixed thereon, and having provision for holding one or more antenna rods.

Still another object of the invention is to provide an improved and adjustable di-pole unit including a pair of complementary rod-holding and pole-engaging elements adapted to insulatedly hold a pair of antenna rods and having surfaces firmly gripping the circumference of the pole for permanently fixing the complete structure in its adjusted position.

It is also within the contemplation of the invention to provide an adjustable di-pole unit having excellent mechanical and electrical characteristics and retaining such characteristics indefinitely under the most rigorous operating conditions.

The invention also contemplates a novel adjustable di-pole unit which is extremely simple in construction, easy to install and to adjust, and which may be readily manufactured and sold on a practical and commercial scale at a low price.

Other and further objects and advantages of the present invention will become apparent from the following description, taken in conjunction with the accompanying drawings, in which Fig. 1 illustrates a perspective view of a preferred embodiment of the present invention into an adjustable di-pole unit;

Fig. 2 depicts a top elevational View, somewhat fragmentary in character, of the di-pole unit shown in Fig. 1;

Fig. 3 shows a perspective view of the rod-holding and pole-engaging elements;

Fig. 4 is a perspective view, somewhat diagrammatic in character, of a pair of di-pole antenna units, each unit being individually adjustable in its vertical plane, and in the horizontal direction with respect to a horizontally extending pole; and

Fig. 5 is a similar view of three di-pole units mounted on a vertical pole and adjustable thereon in height and direction.

Broadly stated, in accordance with the principles of my invention, I provide a pair of rodholding members adapted to receive and to hold a pair of metallic rods. In view of the fact that the metallic antenna rods have to be insulatedly held in space, I prefer to make these members from an insulating material having great mechanical strength and rigidity and capable of resisting the detrimental influence of the elements. Such a preferred material is particularly porcelain, which has the advantage of low cost, great strength and excellent insulating properties. Obviously, other insulating materials may be employed with equal or similar results, such as synthetic resins, plastics, and the like. It is likewise possible to employ metallic rodholding members in which insulating elements, bushings, and the like, may be inserted to provide proper insulation of the antenna rods, as those skilled in the art will readily understand.

The rod-holding members are provided with surfaces adapted to engage the circumferential surface of a mounting pole. These engaging surfaces are preferably conforming to the cross section of the pole and may be provided with ridges or similar gripping elements firmly gripping the circumference of the pole and preventing displacement or slipping of the unit with respect to the pole. To assure positive gripping action of the rod-holding members upon the pole, I provide means for pressing the rod-holding members against the pole from two opposite directions. These means may comprise, for example, a pair of bolts and nuts passed through corresponding openings in the extremities of the said rod-holding members which are placed face to face with the cross section of the pole interposed therebetween. Upon tightening the nuts on the bolts, the two rod-holding members will be pressed against the surface of the pole from two opposite directions and will exert a powerful gripping action thereon so that displacement of said member either in the horizontal or in the vertical plane with respect to the pole is impossible. In the simplest case, the antenna rods and the fixing bolts may be integrally formed from the same metallic rod whereby further simplification of structure and of operation are obtained. In this case, the ends of the antenna rods are threaded and the rods are provided with shoulders or similar portions of increased diameter at an appropriate distance from their ends. The ends of these rods are passed through openings provided in the rod-holding members and cooperate with nuts whereby upon tightening said nuts the shoulders will engage the outer surface of the rodholding members in proximity to the openings and will press the rod-holding members against the pole, thereby fixing both the rods with respect to the rod-holding members and the rod-holding members with respect to the pole.

The invention will now be more fully described to those skilled in the art, reference being had to the accompanying drawings.

Referring now more particularly to Figs. 1 to 3 of the drawings, they illustrate a preferred embodiment of the present invention. Reference character denotes two rod-holding members, preferably made of porcelain, or some other insulating material. These members are of a generally oblong shape except for curved surfaces H which are so constructed and arranged as to conform to the circumferential surface of pole upon which they are mounted. Ridges or similar gripping elements l2 are provided on curved surfaces H, as this will be best observed in Fig. 3. In view of the fact that for electrical reasons pole 2D is generally constituted of wood, these gripping elements will be pressed into the outer surface thereof and thereby further improve the gripping action, as it will be explained more fully hereinafter.

The antenna rods are denoted by reference character l3 and may be constituted of copper,

axis of the pole.

brass, stainless steel, iron, or some other similar metallic material. Rods l3 are threaded at one of their ends as indicated at M and at an appropriate distance from that end are provided with shoulders H). The terminal portion of the rods is of such diameter as to fit into corresponding openings l6 provided in the rod-holding members see Fig. 3) and are provided with shoulders of slightly greater diameter to prevent the rod from slipping through theopening into which it is inserted. Wing nuts I! are applied to the threaded ends of the rods. Preferably, a washer I8 is placed between the wing nuts and the adjoining surface of the rod-holding members, this washer having an extension or lug to which the ends of a twisted transmission line l9 may be soldered.

From the foregoing description, the operation of my novel adjustable antenna unit will be readily understood by those skilled in the art. First the two rod-holding members are applied in diametrically opposed position to the circumference of pole 20 so that their curved pole-engaging surface H is applied against the corresponding surfaces of the pole. Hereafter, the threaded portions of antenna rods l3 are passed through openings E6 of both rod-holding members l0 so that the two rods extend into opposite directions, and then washers l8 and wing nuts I? are placed in their proper positions on the threaded ends of the rods. While the structure is merely loosely held together by the nuts, the rod-holding members may be readily displaced on the pole in the vertical direction and may be also rotated about the pole in a plane vertical to that of the After the desired adjustment of the di-pole unit has been obtained, wing nuts I? are tightened. Due to the fact that shoulders l5 of rods I3 prevent the rods from slipping through openings iii of the rod-holding members, upon tightening of the nuts the two members will be strongly pressed against the circumferential surface of the pole and in case the pole is constituted of wood, ridges l2 will actually dig into the material of the pole so that any displacement of the unit will be positively prevented. It will be noted that tightening of nuts I! simultaneously and positively fixes both the position of the antenna rods with respect to the rod-holding members, and the position of said members with respect to the pole. The received signal may be transferred to a receiver either directly or through a suitable coupling unit through transmission line l9 which is electrically connected to the rods by means of washers and lugs Hi.

In some instances it is found desirable to mount a plurality of my novel adjustable di-pole units on a single supporting structure in order to solve special problems in the reception, or transmission, of short-wave, television, or frequency-modulated signals. Examples of such installations are shown in Figs. 4 and 5. In Fig. 4 there is illustrated a vertical pole 30 having a transverse arm 3| secured thereto by means of a T-shaped connecting member 32. At each end of said transverse arm there is mounted an adjustable di-pole unit generally denoted by reference character 33 and comprising rod-holding members 34 and rods 35. Each of these units may be individually adjusted along the transverse arm and also around said transverse arm. An antenna structure of this character is particularly useful in the reception of television and frequency-modulated signals, one di-pole unit being preferably used for the reception, the other as a reflector.

A similar arrangement is shown in Fig. 5 in which a vertical pole 40 carries three, or more, di-pole units 4 I, l2, 43, each comprising rod-holding members 44 and rods 45. Each of these units is adjustable along and around the common supporting pole until optimum operating conditions are obtained. An arrangement of this type is sometimes referred to in the art as a "turnstile type antenna and finds many applications in the transmission and reception of short-wave, television and frequency-modulated signals.

It will be noted that the adjustable di-pole unit of the present invention provides various important advantages. Thus, first of all, a novel and improved di-pole unit is provided which may be easily mounted on any pole, or similar supporting element and may be readily adjusted and positively fixed at a moment's notice.

It is also to be observed that the di-pole unit of the invention combines excellent electrical characteristics with great mechanical strength and ruggedness and is capable of resisting to the elements indefinitely.

Moreover, the di-pole unit of the invention is extremely simple in construction and has only few and simple parts so that it can be manufactured and sold at a cost substantially below that of prior devices.

Although the present invention has been described in connection with a preferred embodiment thereof, variations and modifications may be resorted to by those skilled in the art without departing from the principles of the present invention. I consider all of these variations and modifications as within the true spirit and scope of the present invention, as disclosed in the foregoing description and defined by the appended claims.

I claim:

1. An antenna unit comprising in combination a pair of rod-holding members constituted of insulating material, each of said members being adapted to receive and to hold a metallic antenna rod and having a pole-engaging surface, means for holding said members in oppositely spaced position with respect to an interposed pole, and means for fixing said members with respect to said pole so that the said rods will extend in substantially opposite direction.

2. An antenna unit comprising in combination a pair of rod-holding members constituted of insulating material, each of said members being adapted to receive and to hold an antenna rod and having a pole-engaging surface, bolting means extending through openings in said members to press the same in opposed complementary position against an interposed pole and thereby adiustably fix the position of said members and of said rods along and about said pole, and gripping elements incorporated into aid pole-engaging surfaces to further improve the gripping action.

3. An antenna unit comprising in combination a pair of elongated insulative rod-holding members, each of said members being adapted to receive and to hold an antenna rod and having a curved pole-gripping surface, a pair of openings extending in the terminal regions of each rodholding member, and means including a pair of bolts each extending through one opening of each rod-holding member to hold said members in parallel-spaced position with their pole-engaging surface facing each other and with the antenna rods extending into opposite directions whereby upon tightening of said bolts the position of said members and of said rods may be fixed with respect to a mounting pole interposed between said gripping surfaces.

4. A di-pole antenna unit comprising in combination a pair of rod-holding members, each having an opening at either end, a pair of antenna rods, each having one of its terminal portions extending through one opening in each of said members to hold said members in parallel-spaced position, and means cooperating with the ends of said rods for pressing said members against an interposed mounting element.

5. A di-pole antenna unit comprising in combination a pair of elongated rod-holding members constituted of an insulating material, each of said members having an opening in each end, a pair of antenna rods, each having a threaded terminal portion extending through one opening in each of said members to hold said members in parallel-spaced position and with the other end of said rods extending in opposite directions. a threaded element cooperating with the threaded end of said rods, and a shoulder on each of said rods respectively engageable with the outer surface of said rod-holding members whereby upon rotation of said threaded elements said rod-holding members will be firmly pressed against the circumferential surface of a mounting pole interposed therebetween and said rod-holding members and said rods may b positively fixed with respect to said pole.

6. A di-pole antenna unit comprising in combination a pair of elongated insulative rod-holding members, each of said members having an opening through each end and a curved pole-engaging surface in its intermediate portion, a pair of metallic antenna rods, each of said rods having a threaded small-diameter portion extending through one opening in each of said members and a shouldered portion extending in the opposite direction from said member to hold said members in parallel-spaced face to face position, and a threaded female element for the threaded end of each of said rods whereby upon rotation of said elements the pole-engaging surfaces of said rodholding members will be firmly pressed against the circumferential surface of a mounting pole interposed therebetween and the position of said rod-holding members and of said rods may'be adjusted and may be positively fixed with respect to said pole.

'7. A di-pole antenna unit comprising in combination a pair of rod-holding members, each having an opening at either end, a pair of antenna rods, each having one of its terminal portions extending through one opening in each of said members to hold said members in parallel-spaced position, means cooperating with the ends of said rods for pressing said members against an interposed mounting element, and a transmission line electrically connected to said rods.

8. In an antenna system, the combination comprising a plurality of dl-pole units: each of said units including a pair of rod-holding members adapted to individually receive and to insulatedly hold an antenna rods and having a surface engageable with the surface of a common mounting pole interposed therebetween, and fixing means for pressing said members towards each other and against said pole thereby to fix the position of said members and of said rods with respect to said pole.

ALFRED FENER. 

